Automatic tuner



June 6, 1950 R. E. THOMPSQN AUTOMATIC TUNER Filed Jam. 19, 194e 7 Sheets-Sheet 1 j Q Q -IllIIJLPl www R. E. THOMPSON AUTOMATIC TUNER June 6, v195o 7 Sheets-Sheet 2 r L\\\\\\\\\\\\\\\\\\\\\Y Filed Jan. 19. 1948 INVENTOR.

June 6, 1950 R. E. THOMPSON AUTOMATIC TUNER '7 Sheets-Sheet 3 Filed Jan. 19. 1948 l EIQ/VENTOR.

gym ZUQUSOYZ,

R. E. THOMPSON AUTOMATIC TUNER June 6, 1.950

7 Sheets-Sheet 4` Filed Jan. 19. 1948 lian ii 1 u JNVENTOR. @//mdf/zo June 6, 1950 R. E. THOMPSON AUTOMATIC TUNER Filed Jan. 19, 1948 7 Sheets-Sheet 5 ma@ @E JN V EN TOR. ZdZf/wzsonf,

June 6, 1950 R. E, THOMPSCN AUTOMATIC TUNER 7 Sheets-Sheet 6 Filed Jan. 19, 1948 mmww www ww l T/215mm.

H/BY ae/fm June 6, 1950 R. E. THOMPSON 2,510,156

AUTOMATIC TUNER Filed Jan. 19, 194s 'r sheets-sheet v INVEN TOR.

)USUM l/ m Patented `lune 6, 195.0

AUTOMATIC TUNER Reynald E. Thompson, Chicago, Ill., assignor to Motorola, Inc., Chicago, Ill., a corporation of Illinois Application January 19, 1948, Serial No. 3,048

18 Claims.

This invention relates to automatic tuners for radio receivers, particularly of the type in which the tuning elements are adjusted to preselected positions by means of push buttons or analogous members acting through the medium of a carriage and stop mechanism.

In mechanisms of the aforesaid type it is desirable that the tuner function accurately with imperceptable or negligible noise and jarring of the parts, and that it be easily set up or adjusted for selection of the required radio stations or frequency channels. It is also desirable that the dial indicator of the radio set be operated so as to give visual indication of the station selected by the listener when the receiver is being tuned automatically.

A general object of the invention is to provide all of the foregoing features in an automatic tuner of novel construction which is economical to manufacture and dependable in operation.

A further object is to provide a combination push-button and manual tuner in which the manual tuning device is instrumental also in setting the stops of the push-button tuning devices.

A still further object is to provide an improved tuner which is compactly arranged, yet permits ready access to its constituent parts.

A still further object is to eliminate solenoids and the like in the tuner mechanism.

A feature of this invention is that each of the station-selecting push buttons is effective, when pressed, to produce a single back-and-forth excursion of the carriage while concurrently moving one of the carriage stops into an interfering position. The arrangement is such that the carriage always returns against the selected stop from the same direction.

Another feature is that the operation of presetting or adjusting the carriage stops (which commonly is referred to as setting up the push buttons) is accomplished by pushing each button individually to a special position, then rotating the manual tuning knob until the desired station is tuned in.

Still another feature resides in a novel mechanical movement for interconnecting two parts whose motions are at right angles to each other, whereby the dial indicator is positioned concurrently with the carriage. The relationship between the positions of these two parts is the same regardless of whether the radio set is being tuned manually or automatically.

For a better understanding of the invention, reference is had to the following detailed description thereof taken in conjunction with the accompanying drawings, wherein:

Fig. 1 is a top plan view of a tuning unit constructed in accordance with and embodying the principles of the invention;

Fig. 2 is a vertical sectional view of the tuning unit taken on the line 2-2 in Fig. 1, looking rearwardly;

Fig. 3 is a bottom view of the unit;

Fig. 4 is an end View looking from the right in Fig. 1;

Fig. 5 is a partial right-end view showing certain parts of the unit moved from the positions thereof shown in Fig. 4;

Fig. 6 is an end view looking from the left in Fig. 1;

Fig. 7 is a horizontal section taken substantially on the line 1--1 in Fig. 2;

Fig. 8 is a sectional View on the line 8-8 in Fig. 7; and

Fig. 9 is a fragmentary view taken on the line 9 9 in Fig. 8 and showing, in elevation, a carriage stop and certain associated parts.

In carrying out the principles of the invention, I have arranged the push-button tuning mechanisrn in such fashion that pushing a button serves to cock and release a spring-biased carriage, while concurrently selecting one of a plurality of carriage-arresting stops and moving such stop into a position for engaging the carrige on its return stroke. The carriage stops are threaded on screw members which may be rotated to set the stops in preselected positions. Each push button is mounted on a plunger having a portion adapted to cooperate with one of a plurality of elongated rocker members which respectively are mounted pivotally on the screw members, the stops being slidably connectedl to the rocker members. The plungers respectively are provided with slide portions for engaging and cocking the carriage mechanism whenever a push button is pressed. These slides do not remain latched-in, as do the plungers, but are automatically released at the appropriate time to initiate the return stroke of the carriage, thus bringing the carriage against the selected stop.

The tuner has a manual tuning knob which directly actuates a screw member on which a carriage stop is mounted. This stop is rendered effective by a manual push button. Shiftable gear trains interconnect the screw member of the manual constrol device selectively with the screw members supporting the carriage stops of the automatic station-selection push buttons, for setting the latter stops individually when it is desired to set up the push buttons for automatic tuning. Each station-selecting push button has a special position in which it may be held to couple its associated screw member with the manual tuning device.

Identification of the station, wave length or frequency channel to which the radio set is automatically tuned by the tuner is afforded by connecting the dial pointed to the aforesaid carriage through the medium of a mechanical move- 3 ment which relates the carriage displacement to the displacement of the pointer in the same manner as though the set were being tuned manually.

Referring now to the drawings and partcularly Figs. 1,14 and 6 thereof, the tuning device illustrated therein is adapted to control tuning elements in the form of variable inductors I having cores or slugs l2 which are movable lengthwise for varying the inductance of the tuning elements. ln these views there are shown three of the inductors I8, which are adapted to be inserted respectively in the oscillator circuit, antenna circuit and an R. F. tuning circuit of a superheterodyne radio receiver, It wiil be understood, of course, that the invention is not limited to three tuning elements, as it will also accon modate a greater or lesser number as circumstances require.

r:the tuning unit isadapted to be mounted in the chassis of the radio receiver and is suitably constructed for ready insertion `therein .and removal therefrom. The frame of the tuner includes a substantially C-.shaped piece it tofwhich is secured a bracket i8. vPlungers I8 (sometimes described as push rods) extend through slots in the frame piece I and the bracket |6,.in which they are slidable. rlhese plungers I8 extend horizontally through suitable apertures in the control panel (not shown) ci the radio set, and push buttons (not shown) are .mounted on the ends of the plungers I8. (In a broad sense, the term push buttons may be regarded as denoting both the push buttons themselves and the associated plungers I8, and `occasionally the expression is used herein in that manner.) When a .pushbutton is pressed inwardly, the connected plunger I8 moves rearwardly against the action of an individual restoring spring 2e, Figs. 4 and 6. The plungers i8 are formed from suitable flat stock which is suitably hardened to withstand wear.

Associated with each plunger I8 is a slide 22, shown best in Fig. e. The slides .22 are .disposed respectively adjacent the plungers I8 and are slidably supported in apertures provided therefor in the frame piece ill and the bracket i6. Shoulders are formed on the slides 22 to limit vthe sliding movement thereof so that they cannot fall out of the tuning unit. Shoulders or lugs likewise are formed on the plungers against a strip of felt 24, Fig. 4, on an inner surface of the frame piece lI4 when the plungers are released to the action of their springs 28. The functions performed by the plungers i8 and slides 22 will become more apparent as the description proceeds.

For actuating the slugs or cores i2 and tuning inductances I8, I provide a carriage structure generally designated 25, Figs. l, 2, 4 and 6. This carriage structure comprises a carriage proper 28, which consists of a plate having apertured lears 38 for slidably supporting the carriage 2S on guide rods 32 mounted in the tuning unit. One .end of each rod 32 extends through holes in a flange 34 `of a frame plate 36 which is secured to the frame piece I4. 'The plate 38 extends horizontally and is anchored to .a vertical supporting plate 38 that likewise is secured to the frame piece lli.

A bracket 48 secured to the supporting plate 88 and the frame plate 38 supports the stationary portions of the tuning inductances 0. The movable vcores l2 are connected by studs i2 to a movable bracket or extension secured to the Ycarriage 28 `and constituting part of the .carriage I8 to strike structure 26. Conventional adjusting devices, including the studs d8, enable the positions of the slugs t2 relative to the carriageextension d4 to be adjusted. The tuning inductors iii, slugs l2 and extension M are disposed above the frame plate 3B, while the carriage 28 is below the frame plate 35. Arms d8 at either end of the extension lextend past the side edges of the plate 36 for connecting the extension @s to the carriage 28.

Links i8 are pivotally connected at their ends to shoulder rivets 58 and 52 respectively located on the arms S8 and on the free ends of rockable drive arms 54. Springs 5E are extended between the rivets 58 and 52 to hold these rivets tightly against the .edges of Athe holes in the `links .58, thereby maintaining a constant relationship .between the carriage and the rocker arms .511. The drivearms Ell are pivotally supported by and secured to a rock shaft 58 extending along the bottom of the unit and journalled at its ends in ball bearings Vtil carried by the bracket I6, as shown in Figs. l and '.1. Coil springs v82 are extended respectively between the arms 54 and the frame piece ibi to bias the carriage structure 28 forwardly, or to the right as viewedin Fig. 6. If desired, one of these springs '82 may beomitted, provided the carriage structure is made sufliciently rigid.

Provision is made for selectively arresting the movement of the carriage 28 under the influence of the springs 52, thereby to adjust thepositions of the movable cores l2 relative to the stationary coils of the tuning inductcrs i8 for deter.- mining the frequencies to which the receiver may be tuned automatically. To this end I have arranged carriage stops E6, Figs. 6, '7, and 8, on threaded shafts or screw members 68 which extend between and are rotatably mounted in the ends of the C-shaped frame piece i4. The stops 86 are threaded on the screws 88 and are capable of limited rotation thereon, into and out of the path of movement of the carriage 28. Each of the stops S8 is allocatedrespectively to-one ofthe plungers I8 which support the automatic stationselecting push buttons, these being identified custornarily by the call letters of radio stations.

A special stop GTI-and a screw member c-r shaft 89, Figs. 4, '7 and 8, are locatedat the right-hand side of the tuning unit. The stop 5'! is allocated to a plunger i8 that carries a push button designated Manual (or the equivalent thereof) which is utilized in manually .tuning the receiver independentl of the automatic tuning devices.

Disposed adjacenteach screw .member 88 or S9 is a rocker 'lil 4of elongated arcuate shape, which is pivotallysupported at its ends on the vscrew member 68 or 68, as the case may be. Individual coil springs 12, best shown in Fig. 8, extend from ears on the rockers l' to the frame piece i4. As shown in the detail view, Fig. 9, each stop 66 (or 8l) has a lug or ear lli thereon which is received in a longitudinally extending slot 'E8 in the rocker 'i8 adjacentthereto. rl'hus, as the stop is positioned longitudinally of the lead .screw on which it is mounted, it may slide relative to the rocker le and yet becaused to turn, on its screw axis whenever the corresponding rocker 'i8 is actuated.

lEach rocker 70 has an ear 18, Figs. 6, '7, and 8, which is urged against the edge of a plunger i8 by the spring 'l2 acting on this rocker. Normally, when the plunger I8 is in its extreme forward position to which it is urged by its spring 20, the ear 18 is positioned at the highest point on an -incline 88 formed on the edge of the plunger I8. This causes the associated carriage stop 66 (or 61) to be positioned out of the path of travel of the carriage 28 (as in the case of the stops 66 and 61 in the right-hand portion of Fig. 8). When a plunger I8 is pushed in, however, the ear 18 on the associated rocker 10 rides down the incline 88, as shown in Fig. 6, whereupon the corresponding spring 12, Fig. 8, rotates the rocker 18 about the screw member 68 as an axis, thereby to dispose the stop 66 (or 61) in a position to arrest the carriage 28 when the latter moves forwardly.

Releasable latching devices are associated with the various plungers I8 so that as each plunger is pushed inwardly to an active position, it is automatically latched in such position, and any previously pushed plunger I8 is thereupon released to the action of its restoring spring. As shown in Figs. 3, 4 and 5, a latch plate 84 is pivotally mounted on the bottom of the frame piece I4 and is yieldingly urged upwardly by a leaf spring 86. Each plunger I8 has a dog 88 thereon which normally is received in an aperture 88 in the latch plate 84. When the plunger I8 is pushed, however, a cam edge on the dog 88 bears against a rib 92 on the plate 84, causing the plate 84 to pivot downwardly away from the frame piece I4. The continued inward movement of the plunger |8 causes the dog 88 to move past the rib 92 and enter another aperture 94 in the plate 84, enabling the latch plate to be restored by the spring 86. The dog 88 seats against the rib 92 when pressure is removed from the push button, and it keeps the plunger I8 latched until actuation of another plunger takes place. As the dog 88 of each actuated plunger I8 presses against the rib 82 to tilt the latch plate 84 as just described, the dog 88 of a previously actuated plunger I8 is disengaged from the corresponding rib 92, and the latter plunger is released. Thus, there can be only one plunger I8 latched-in at one time, provided that the push buttons are p-ressed consecutively and not simultaneously.

It has been mentioned hereinabove that the carriage structure 26 is caused to make an excursion back and forth each time a plunger is pressed inwardly. A rod 96, Figs. 1, 5, 6 and 8, extends between the drive arms 54 which carry the carriage structure 26, the ends of this rod 96 being rotatably received in the arms 54. Each of these slides 22 carried by the plungers I8 has a shoulder adapted to bear against the rod 96 when the plunger I8 is pushed inwardly. The slide 22 is connected to the plunger I8 by a pawl 98 pivotally mounted on a plunger I8 and normally urged bya small coil spring |08 into a notch or recess |82 in an edge of the slide 22. Each pawl 98 has a tail |84 extending to an aperture |86 (Fig. 3) in the frame piece I4. During the greater part of the inward travel of the plunger i8, the tail |84 travels along the aperture |86 and the pawl 98 is seated in the notch |82, so that the slide 22 is forced to travel with the plunger I8. Consequently, whichever slide 22 is actuated bears against the rod 96 and pushes the rocker arms 54 rearwardly, thus causing the carriage mechanism 26 to be cocked. Toward the end of the rearward travel of the plunger I8 and the carriage structure 26, the tail |84 of the pawl 98 strikes a rib |88 in the frame piece I4, and continued inward travel of the plunger I8 produces a rocking of the pawl 88 about its pivot so that the pawl becomes unseated from the recess |82 in the slide 22. Thereupon the restoring springs 62 of the carriage are effective to push the carriage struc- 6 ture 26 (as well as the now-released slide 22) forwardly again. The various positions which the rocker arms 54 and other carriage parts may occupy in the course of an excursion thereof are indicated in broken and full lines, respectively, in Fig. 4.

It will be seen from the foregoing that each actuation of a plunger I8 produces a back-and-forth excursion of the carriage 26. It will be recalled also that by pushing a plunger I8 inwardly, the associated stop 66 (or 61) is caused to occupy a carriage-arresting position. The carriage proper 28 is a substantially flat plate having a substantial width so that it would be impossible for a carriage stop to move into an interfering position in back of the carriage 28. If a carriage stop as 66 is released to the action of its spring 12 before the carriage 28 has travelled rearwardly a sufficient distance to clear the stop, the stop will merely bear against the side of the carriage until the latter has been moved rearwardly past the stop, whereupon the stop will immediately swing in front of the carriage to arrest the same on its return stroke.

As mentioned above, the carriage stops 66 (of which there are iive in the illustrated embodiment) are respectively associated with automatic station-selecting push buttons and associated plunger devices of the tuning unit. These stops must be set up for arresting the carriage 28 at proper positions whereby the tuning slugs I2 are adjusted to the necessary frequencies for tuning in the desired stations. Before explaining the manner in which this is done, however, a description will rst be given of the manual tuning arrangement, inasmuch as this arrangement is instrumental in setting up the other carriage stops.

A gear H0, Fig. 8, is fast on the screw member 69 just inside the front wall of the frame piece I4. This gear is meshed with an idler pinion ||2 rotatably mounted on a stub shaft ||4 journalled in an ear ||5, Fig. 2, on the frame piece I4. The pinion ||2 is adapted to mesh with a gear H6 (Figs. 2 and 8) on a manual tuning shaft ||8 which usually is journalled in the chassis (not shown) of the radio set. This shaft ||8 may be provided with a knob or other similar device to facilitate turning the shaft ||8 by hand. For manual tuning of the receiver, the manual push button is pressed, causing the extreme right-hand plunger I8, as Viewed in Figs. 1, 2 and 8, to move in and position the carriage stop 66 in carriage-arresting position. Then, as the manual tuning shaft ||8 is turned, the screw 69 is caused to rotate, thereby moving the carriage stop 61 along the screw-threaded portion of the shaft 69. As is usual for each actuation of a push button, the carriage 28 is freed from the control of any previously active carriage stop and is brought against the newly selected stop (in this case, the stop 61). Hence, the carriage 28 will follow the movement of the stop 61 along the screw 69 in this operation, producing a continuous variation of the frequency to which the radio receiver is being tuned so long as the tuning knob is rotated.

If the stop 61 should attempt to travel rearwardly past the threaded portion of the shaft 69, further travel thereof is prevented by a coil spring |28 (Figs. 4 and 7) which is wound around and Aunthreaded end portion |22 of the shaft 89, this end portion |22 being of smaller diameter than the threaded portion. Therefore, any attempt to screw the stop 61 in farther than the extent of the threads on the shaft 69 will result 7 ymerely in .the compression: of the coil spring lf2@ while it vmaintains the stop e9' against the Ainner end of the threaded vportion of the shaft 69. Likewise, Aat the forward end ot the screwr te -there is' 'a -co'il spring 12d on a thinner, unthreaded portion IES of the shaft 553. when the stop 'ireaches the forward end of its travel on the threaded portion oi shaft TES, continued rotation of .the vshaft 6e in the same direction causes the stop Si to ride on the threaded portion, but .it will be held back against the' end thread by the spring |255'. In the' Ycase 'oi lthe five :lead screws or threade'dsh'a'f-ts '653, each ofthe 'carriage stops 165 mounted thereon islimited in its forward motion by a lead screw shoulder |23 and in 'its vbackward motion by the length -o' the' slot 'itin the rocker 10.

Adjacent the inside rear face o'fthe frame piece Id is 'disposedsuitable gearing for selectively/'coupling the' manually operated shaft' 53 to "theshats 68, thereby to set up the carriage stops E. A `pinion I3il, Figs. 4 and 8, fast on the inner end of the sh'ait 'Se is adapted to mesh with a pinion |32 which is mounted on a shirtM ably supported stub .shaft |3. A coill spring its disposed on the stub shaft It between the pinion |32 andthe rear face of the frame piece tends to urge the 'pinion |32 'into a position where it is' meshed with the pinion les' on' one side and with 'another pinion i353 on the other side. There arelseve'ral 'of the pinions |33 (in this instance, ve) which are mounted on sh'irtable stub shafts Idil that are urged by springs I vforwardly so that normally all of the pinions |33 vare in m'esh with one another. Eacho'f the stub' shafts Idil' may be pushed rearwardly to engage its pinion |38 with a 'pinion Idil, Figs. 6 and 8, fast on the rear portion of one of the screw members 68'.

Referring now to' Fig. 4, when the push rod or plunger IS which carries the manual push button is pressed in and latched, the inner end of this plunger strikes va button If' on the forward end of the stub shaft |36 and pushes the shaft' |34 and pinion |32 rearwardly to disengage the pinion |323 from the pinion |23. Hence, during manual tuning of the radio set, the lead screwv 591v is disengaged from the train of gearing just described so that the frictional resistance to rotation of 'the screw is minimized. When oneo'f the other push buttons is actuated, the plunger I8 just referred to is released, and the pinion |32 moves bacli: into engagement with the pinion I 30.

When a station-selecting push button is to be set up, the button is pushed inwardly past its usual latched-in position, as far as it will go, and is held in that' position manually. Depending upon which pushv buton is actuated, one of the pl-ungers 'I8 willy strike al button |48 on a stub shaft ld, Fig. 6, and push the stub shaft |49- and its associated pinion |38A rearwardly. This brings the pinion |33 into mesh with a pinion I M of the lead screw 63 which is associated with the pushed-in plunger. When the pinio'ns |38 are moved rearwardly in this fashion, they still remain in mesh with' each other so that a continuous gear train is afforded from the selected pinion l'-t to the driving pinion |35 on the manually actuated screw member or shaft Hence, the selected screw member or shaft d8 may beV rotated in unison with the shaft 69, causing the selected carriage stop et to travel along the threaded portion of the shaft 68. The carriage 28, meanwhile having been cocked and 8. released-as an incident to the-actuation ofYV 'the plunger' I3, 'follows the motion 4of the Yselected carriage stopftl.v Thus, the frequency to which the radio set is tunedb'y any -o'f the station-se'- leeting buttonsV may be varied by means of the Imanual `turning k-nob.

'When thesetting-fup operation for 'a particu-V lar push button i-s'completed, pressureV is're'move'd firorn' thatbutton-,and the spring 29 acting thereonv 4res-tores the plunger to its lla'tched--iny position, `where i-t `is-heicl ley" the dog `88until released. In this-position o'f the plunger' I8, it is `disengaged tromthe stuo shaitI Illyenabling the sprimg; M2 tadisengage the pinion |38 from the gear |44, so th-'at rotation. of the Vrrran'ua'l tuning mem-ber has. ne further eirect'V upon the setting of' the carriage stop 66.

The 'foregoing cperation'of setting up push button, that is, s'ettir'ig its vassociated* carriage stop t6, may be repeated for other buttons until all thecarriage stops *tl have been set 'intoV the requisite positions.

The lcarriage -2-53 `or the tuner is connected to the mechanism which drivesthe pointer or' Adial indicator of the radio receiver. It is' desirable that the pointer' have a substantially"straightlinev motion which bears more or iess of Va 'propo-rtionate relation to the displacement of the carriage lfrom' its fully-cocked position, and it vris further 'desirable that the pointer' 'be' actuated 'to indieate the sta-tions, channels Aor 'wave lengths selected by the listener irrespective of whether the tuner is being operated manually or' auto-A matically. For this purpose l have lprovided a mechanical movement which is best illustrated in lFig. 1, this movement ybeing interposed 'between the carri-age 258 and the pointer; A triangular lever 52, fulcru-med at Palit on the frame/plate' '36, is disposed immediately "beneath lan opening V58 in the plate A second lever |5tl'is fulorum'ed `approximately at its'inid Vpoint on the lever |152', as indicated at Iliad. 'I Vhe rearwardly extending portion of this leverI'icarries a pin' twhich is received in a Sio-t its v'formed inthe frame'v plate 362 The slot Il extends parallel to thepath of movementof vthe 'carriage 2t, that is, straight rearwardly. Thus the rear 'end of the lever" |53 isV constrained to move in a straighte'line' path parafileling the-path' of" the carriage' 2t; rEhe' forward end ofk the lever IEl terminates i'n a free endl `|162 which is connected to the' pointer (not shown) cooperating with the vdial of the radio receiver. A third lever It* isfulcrumed at It on the' carriage E8 and is` pivotally connected to the lever 6'5'2 between (but not necessarily in alignment with) the lever iulc-ru'msv tt and' i54 thereon'. This pivotal connection preferably is afforded by a pin or rivet Hi8 on the lever |512 received Vin a slot 'Il-i2 in the lever |641; A leaf-- spring I'i anchored to the frame piecer l'liand acting upon theV lever |52 tends tor maintain the pin ltseated in one end of the slot Il, yet permitting thepin i' to ride alo-ng theslot I'i'l vthe lever |56 reaches its extreme rearward position.

The lever arrangemen-t just described affords a compound motion whereby the displacement or the carriage 2S* is sol related to Vthe displacement or' thefrpointer attached to 'the' end F62 of the lever' its' that a Atrue indication '0f the tuning is obtained. The various positions which these levers may occupy' for different positions of the carriage` 23" are' shown in broken and full lines, respectively, in Fig. i. The restoring springs t2 for theca'rriage t'tend tourge the pointer mechanism to the left (as viewed in Fig. l) while the carriage is travelling forwardly. The pointer is moved to the right when the carriage is travelling rearwardly.

The above-described tuning apparatus greatly expedites automatic tuning operations in radio receivers and the like. The mechanism functions quietly and accurately. Setting-up of the push buttons is accomplished with ease merely by pushing each button in turn to the extreme limit of its inward travel, beyond its latched-in' position, and turning the manual tuning knob until the desired setting is achieved. The dial pointer always indicates the tuning of the receiver for both automatic and manual tuning operations. While the tuner has been illustrated and described as being mounted so that the push buttons are in a horizontal row, it may be positioned also with the buttons aligned vertically.

While a preferred embodiment of the invention has been disclosed herein, such embodiment obviously is capable of modification without departing from the spirit of the invention, and it is intended to cover all such modications by the appended claims.

I claim:

1. In an automatic tuner having movable tuning elements and a plurality of push buttons for the selective positioning of said elements, the combination of a spring-biased carriage operatively connected to the tuning elements, a plurality of carriage stops each movable into a position for arresting said carriage, a plurality of plunger devices respectively supporting said push buttons, each of said plunger devices having a rst portion cooperating with a respective one of said stops for causing such stop to occupy its carriage-arresting position as an incident to actuation of the plunger device, and a second portion cooperating with said carriage to produce an excursion of said carriage backwardly to a predetermined position and then forwardly into engagement with the stop which is in carriagearresting position, said second portion being releasable from said rst portion, and means for automatically releasing said second portion from said iirst portion at the limit of the backward movement of said carriage whereby said carriage is able to move forwardly while said rst portion is maintaining said stop in the carriage-arresting position thereof.

2. In an automatic tuner having movable tuning elements and a plurality of push buttons for the selective positioning of said elements, the combination of a carriage operatively connected to the tuning elements, a plurality of carriage stops, yieldable means normally tending toY urge each oi said stops into a position for arresting said carriage, and a plurality of plunger devices respectively supporting said push buttons, said plunger devices having lirst portions cooperating respectively with said stops for maintaining said stops away from their carriage-arresting positions except when the plunger devices are pushed in, each of said plunger devices also having a second portion cooperating with said carriage and eiective when such device is pushed in to produce an excursion of said carriage backwardly to a predetermined position and then forwardly into engagement with the stop which is in carriage-arresting position.

3. In an automatic tuner having movable tuning elements, a plurality of push-button devices, interlocking means whereby each of said devices is held latched in when pushed and is released when another of said devices vis pushed, and means to restore the released push-buttons; the combination comprising a spring-biased carriage operatively connected to the tuning elements, a plurality of carriage stops, yieldable means normally tending to urge each of said stops into a position for arresting said carriage, first members actuated by the push-button devices and respece tively cooperating with said stops to maintain said stops away from their carriage-arresting positions, said first members respectively being ineffective when the corresponding bush-button devices are latched in, and second members on said push-button devices cooperating with said carriage to produce an excursion of said carriage backwardly to a predetermined position and then forwardly as an incident to the actuation of a push-button device, said carriage having a dimension in the direction of its travel greater than the maximum displacement between stops so as to prevent the movement of a stop into its carriage-arresting position until said carriage has cleared the stop in the course of moving rearwardly.

4. In an automatic tuner having movable tun ing elements and a plurality of push buttons for the selective positioning of the tuning elements, the combination of a carriage operatively conm nected to the tuning elements, resilient means biasing said carriage forwardly, a plurality of carriage stops each movable into a position for arresting said carriage in its forward motion, a

plurality of plungers respectively supporting said' push buttons, each of said plungers having a portion cooperating with a respective one of said stops for causing such stop to occupy its carriagearresting` position when the plunger is pushed rearwardly, a plurality of slides respectively -mounted on said plungers and releasably coupled thereto, each of said slides being adapted to cooperate with said carriage to retract said carriage rearwardly when the corresponding plunger is pushed, and releasing mechanism eiective on said slides for releasing said carriage to the action of said resilient means at the end of its rearward stroke, while said plunger remains pushed in. y

5. In an automatic tuner having movable tuning elements and a plurality of push buttons for the selective positioning of the tuning elements in predetermined positions, the combination of a carriage mechanism operatively connected to the tuning elements, carriage stop mechanism including a plurality oi carriage stops each ro-y tatably mounted on a shaft, adjusting members for positioning said stops selectively lengthwise of their shafts, a plurality of elongated rockers. respectively extending substantially parallel to. said shafts, said stops having sliding connections with said rockers, and a plurality of plunger devices respectively supporting said push buttons,

i each of said plunger devices having a first portion engageable with a respective one of said rockers for pivoting the same when the correspondingv push button is pressed, thereby to cause the respective stop to be moved into its carriage-arresting position, and a second portion cooperating with said carriage mechanism for producing a back-and-forth excursion of the carriage as an incident to pressing the push button.

- 6. In an automatic tuner having movable tuning elements, at least two push buttons, and a manually rotatable member; the combination of a carriage mechanism operatively connected to the tuning elements, carriage stop mechanism in- 1.1. clnding two carriage. stops respectively. mounted rotatably on shafts',` adjusting members fory positioning said stops selectivelyl lengthwise of. theirv shafts, motiontransmitting. means between said manually rotatable member and oneo'f'said: adjusting members, normally disengaged motion-transmitting devices between, the manually rotatable member and the other of said adjust-- ing members, elongated rockers respectively exn tending. substantially parallel to said supports, said stops having sliding connections with said rockers, and two plunger devices respectively supporting said. push buttons, each of said plunger devices having a first portion engageable with a respective one of said rockers for pivoting. theY same when the push button is pressed, thereby to cause. the respective stop tofbe moved into its carriage-arresting position, and a` secondfportion cooperating. with said. carriage mechanism for producingv a back-and-forth excursion ofthe carriage as an incident to pressing the push button, the plunger device for one of said push buttons also controlling said normally disengagedmoticntransmitting devices and having an optional-pon sition for effecting engagement thereof.

'7. The combination set forth in claim 6, wheren in the. other of said plunger devices is arranged to disengage the last-mentioned motion-transmitting devices when the other of said push buttons is pressed.

8. In. arrautomatic tuner for a radio receiver., movable. tuning elements, a carriage for. movn ing. said elements, a pushF-button mechanism in1- cluding settable. stops for placing said carriage in anyoi a plurality of preselected positions, va rotary device manually operable for placing said carriage selectively'in any position within a given range including said preselected positions, a plm rality of screw members respectively arrangedfto adjust the positions oi said stops along the path` of said carriage, trainsv of gearingl between-said rotary device and said screw members whereby said'rotary device may drive said screw members,

and gear shifters under the control of said push button mechanism for selectively rendering said trains of gearing effective.

9. In an automatic tuner for a radio receiver, movable tuningv elements, a spring-biased car riage for moving` said elements, push-buttonfde vices,` settable stops for arresting said carriagein any ofv a plurality of. preselected posit-ions, each of said stops being movable into'` and out of-a carriage-arresting position, stop-actuating members respectively associatedY with said stops forl individuallyl moving the stopsN into-"and out of their carriage-arresting positions; under control of said'push-button devices, screwthreaded stop-setting members stationarily mounted and separateirom said `push-button devices, a manual.

control device separate from said' push-button devices for placing said carriage selectively in any position within a given range including; said preselecte'd'positions, andshiitable coupling de vices selectivelyv engageable ton establish. operative connections between said manual control device and said stop-setting members for' en- *abling said manual control device to adjust the 12 trol device and a respective one or. saidstopf-settingv members.

l0'. In an automatic tuner fora radio receiver; movable tuning elements, a carriage for moving; said elements, station-selecting push-buttondevices, settffbleA stops for retaining said-carriage in any of a pluralityv of preselected' positions vundercontrol of said push-button devices; manually rotatable means for placing saidA carriage selec tively in any position within a givenrange includingsaid preselected positions, a plurality'ot screw members respectively arranged to adjustthe positions of said stopsalong the'path` ofsaidlcarf riage, elongated rockers pivotally mounted on said screw memberssaid stops:beingfthreade'don saidE screw members and; having portions-'slidingly'connested with said rockers, portions on said pushbutton devices cooperating with said rockersfor turning said' stopsinto'and out ofi their carriageengaging positions depending upon the actuation ofthe push-button devices, trains of gearing between said manually rotatable means and said screw members whereby said rotatable means may drive said screw members rotatively to'. adjust said stops, and gear Shifters under Ycontrol of said push-button devices for selectivelyy rendering said trains of gearing effective'.

1l. Ina-n' automatic'ituner'ior a radio receiver, tuning elementsv having rectilinearly movable portions, a carriageroperatively connectedfto'said movable `portions, raplurality of stationeselecting push-button devices, a manual push-buttonlY device, aplurality'oir screw'members one foreach' ofv said push-button devices andY extending-,parsallel to-thedirection: ofv movement ofv said carV riage;` a plurality of' carriagestops respectively threaded onsaid` screw members, a manuallyro-` tatable member operatively connected toz-one vof said. screwv members for turningthe same whensuchfmember isrotated, a plurality oi gear:trai-nsy forrespectivelycouplingsaidone'v screw memberV to thei remaining screwfmembers; certain civ thegearsin said trains beingshiitable'intofandout ofianv operative relationf or rendering; said-:trains selectively eiective, gear: s-hiizters respectively' controlled by said stationselecting push-button devices for selectively establishingl operativecon-d nections through said gear trains betweeny said one screw Vmember and` theremaining screw mem bers-l to. enable'said stops to -be'set by: said manr ually rotatable member, rockers pivotally mount-Vv ed. adjacent said screw members. said stops respectively having slidingY connections with said rockers, and por-tions'on all saidpush-button des vices. cooperating respectively with said. rockers and with said carriage whereby said stops are: selectively positioned to engage said carriageun der control of said push-button devices, and said carriage is caused to make a single excursion for each actuation ofV a push-button device 12. A tuner as set forth inlclaim l1, .includinga gear shifter under controly of said manual push-button device and effective when suchdevice is actuatedto disenga'ge said one mem.- berv from all -of said gear trains.

13. In a push-button mechanismy having a plu rality of buttons that may be vpushed selectively into active positions, each button when pushed being latched in an active position and effectingV restoration of any previously pushed button to its inactive position, the combination therewith of a carriage biased to move in a given direction, aI plurality ofstopsrespectively settable to-arrest. said carriage in variouspreselected positionasaid stops normally being disengaged' iromfsaid vcarriage, stop-controlling devices connecting each of said push buttons with a respective one of said stops to condition each stop for arresting said carriage as the corresponding push button is actuated, and carriage-actuating devices connecting each of said push buttons with said car riage to produce a single back-and forth excursion of said carriage to bring said carriage against the conditioned one of said stops while travelling in said given direction.

14, In a push-button mechanism having a plurality of buttons that may be pushed selec tively into active positions, each button when pressed being latched in an active position and effecting restoration f any previously pushed button to its inactive position, the combination therewith of a spring-biased carriage, a plurality of stops respectively settable to arrest said carriage in various preselected positions, said stops normally being disengaged from said carriage, stop-controlling devices connecting each of said push buttons with a respective one of said stops to condition each stop for arresting said carriage as the corresponding push button is actuated, a plurality of carriage-actuating devices one for each of said push buttons, and connecting devices respectively coupling said carriage-actuating devices with said push buttons to cock said carriage whenever a push button is pressed, said connecting devices being releasable to uncouple said carriage-actuating devices from said pushbuttons, tripping means for automatically releasing any of said connecting devices when the carriage is fully cocked, thereby to release said carriage for movement into engagement with said one of said stops corresponding to the ac tuated push button.

15. In a tuner for a radio receiver, a plurality of automatic station-selecting push buttons, releasable latching means effective when any of said buttons is pushed inwardly for holding such button in a predetermined position and for releasing any previously pushed button, a carriage, a plurality of settable carriage stops respectively related to said push buttons, rotary adjusting devices for setting said stops, a manually rotatable element for driving said rotary adjusting devices, shiftable couplers interposed between said rotatable elements and said adjusting devices and arranged to be actuated respectively by said push buttons, each of said couplers being rendered effective when its corresponding button is pushed inwardly to an extreme position, and a resilient member for urging each button from its extreme inward position to said predetermined position thereof thereby to disengage the related coupler upon the removal of external pressure from the button.

16. In an automatic tuner having movable tuning elements and a plurality of push buttons for the selective positioning of said elements, the combination of a spring-biased carriage operatively connected to the tuning elements, a plurality of carriage stops each movable into a position for arresting said carriage, a plurality of plunger devices respectively supporting said push buttons, each of said plunger devices having a first portion cooperating with a respective one of said stops for causing such stop to occupy its carriage-arresting position as an incident to actuation of the plunger device, and a second portion cooperating With said carriage to produce a movement of said carriage against the spring bias thereof to a given position as said plunger device is actuated to a predetermined position thereof, and tripping means for releasing said carriage to the action of its spring bias as said carriage attains said given position thereof while said rst portion of the actuated plunger device is in said predetermined position thereof, thereby enabling said carriage to move until arrested by the stop which is in carriage-arresting position.

17. In an automatic tuner for a radio receiver, movable tuning elements, a carriage for moving said elements, station-selecting mechanism including a plurality of reciprocable plungers and a corresponding plurality of settable stops for placing said carriage in any of a plurality of preselected positions, each of said plungers being movable to a given position for bringing said carriage against the respective stop associated with such plunger, a manual control device separate from said station-selecting mechanism for placing said carriage selectively in any position within a given range including said preselected positions, a plurality of shiftable coupling devices for respectively establishing operative connections between said manual control device and said stops for enabling said manual control device to adjust the settings of said stops individually, thereby to determine the positions at which said carriage may be placed by said station-selecting mechanism, each of said coupling devices normally being biased to a disengaged position, each of said plungers having a portion thereof adapted to produce operative engagement of the respec tive coupling device only when such plunger is moved to an extreme position beyond .said given position thereof, and means normally biasing each of said plungers away from said extreme position thereof.

18. In a push-button tuner having a carriage which is movable back and forth in a given straight path for adjusting the positions of tuning elements in response to the actuation of push buttons in the tuner, and in which a pointer is movable in a rectilinear path substantially at right angles to the path of the carriage, mechanism for connecting the pointer to the carriage to indicate the frequencies to which the tuning elements are tuned, such mechanism comprising a first lever having a stationary fulcrum, a second lever fulcrumed on said first lever, a stationary frame having a slot therein extending parallel to the path of the carriage, said second lever being connected on one side of its fulcrum to the pointer and having a portion on the other side of its fulcrum received in said slot, and a third lever fulcrumed on the carriage and having a lostmotion pivotal connection with said first lever intermediate the aforesaid fulcrums of said first lever.

REYNALD E. THOMPSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,214,506 Manning et al Sept. 10, 1940 2,267,474 McGarvey Dec. 23, 1941 2,313,653 Lyman Mar. 9, 1943 2,320,893 Schwarz et al s June 1, 1943 2,338,533 Pash Jan. 4, 1944 2,400,193 Cramer` May 14, 1946 2,453,187 Blain Nov. 9, 1948 

